Collagen is used in a variety of medical applications ranging from hemostatic materials and biocompatible coatings to drug delivery and tissue engineering. Traditionally, collagen is used as passive (but biocompatible) materials that protect injured sites and support healing processes. Today, there is a renewed interest in collagen as bioactive scaffolds that can provide ideal environment for specific tissue formation. This has led to widespread interests in immobilizing bioactive components (such as growth factors, antimicrobial agents, or cell-repellent) to natural collagen. In this proposal we wish to investigate nonchemical immobilization of collagen mimetic peptides (CMP) and CMP derivatives on collagen scaffolds, and explore its potential as a new collagen modification technique targeted for microvasculature engineering. Collagen mimetic peptides (CMPs) are peptides, typically of less than 30 amino acids, composed of multimers of known helicogenic trimers (e.g. ProHypGly). They have been highly useful in determining the structure and stability of natural collagens and their collagen-like triple helical structure and reversible association (melting) behaviors are documented in the literatures. In our previous studies, we discovered that CMPs can bind to collagen films (type I) under controlled thermal condition. Main goals of this research are to further understand the CMP-collagen interaction, identify optimal CMP structure that exhibit efficient and reversible binding to collagen under physiological or near-physiological condition, and demonstrate the practical use of the poly(ethyleneglycol)-CMP conjugate in controlling the endothelial cell (ED) organization in 2D and 3D collagen scaffolds. In the long run, we wish to develop this approach into a more general collagen modification method that can provide novel solutions to complications after vascular and ocular surgery and to add therapeutic activity to conventional collagen-based biomaterials (see support letter from The Wilmer Ophthalmological Institute of the Johns Hopkins Medical School).